We're told the alleged attack went down at L.A. Live while Claudia was walking the red carpet.

Our sources at the awards show say, Claudia and Omarosa got into a heated verbal exchange -- after Omarosa allegedly called Claudia a "stupid b***h."

The verbal blows didn't stop ... so we're told when Omarosa's mom overheard it ... she walked by and punched Claudia in the arm. We're told event security then rushed in to break the women up and prevented the incident from escalating further.

Claudia then tweeted, "Wow, that awkward moment when you're assaulted on the red carpet."

But Omarosa tells TMZ ... Claudia started it by pushing her 65-year-old mother. And Omarosa says her mom filed her own police report for assault against Claudia. She says, “I am deeply saddened by Claudia Jordan actions at the BET Awards. After all that my family and I been through this year. She should show at least an ounce of decency and respect “

FYI -- Claudia and Omarosa were on "All-Star Celebrity Apprentice" together ... and have been known to bash each other in the media.

Specifically Omarosa claims Claudia took pics at Michael Clarke Duncan's funeral (Omarosa's former fiance) which pissed her off. Claudia, in turn, ripped Omarosa, saying she was using the funeral as a press opportunity.